This core will provide tissue culture and animal models for CHAIN investigators. The objectives of this core are to isolate and propagate primary human leukocytes (monocytes and peripheral blood lymphocytes and to provide rodent and primate models of CHAIN. Rigorous quality control measures are in place for this well integrated core. Primary human leukocytes will be fractionated into monocytes and lymphocytes from HIV-1, 2 and hepatitis B and C seronegative donors by centrifugal elutriation. Human glia (microglia and astrocytes) and/or neurons will be obtained from fetal tissues. The neurons and glia from human brain tissue will be purified, characterized and provided for experiments. These will provide data for common endpoints of disease. In toto, this 'cell, fissue, and animal core' will provide all the biological specimens necessary to address research objectives of the center research programs and utilize the carefully controlled specimens obtained through this infrastructure to invesfigate neural immunity and its links to CHAIN. The techniques in the Core as a whole will also support neuroimmunological studies relevant to microglial activation in CHAIN. The results obtained from this core will have direct applicability for determining the mechanisms and monitoring the course of HIV infection in its chronic stage. Our overriding goal is to assist CHAIN Pis and other researchers interested in neuroAIDS in determining and characterizing changes of CNS function as they develop in the various in vitro and in vivo models of neuroAIDS, and in exploring therapeutic potentials aiming at ameliorating or reversing such functional changes